On a grand scale (4)
I believe the answer is:
epic
'on a grand scale' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for epic that I've seen before include "Long literary work about great events" , "On a grand scale like long poem" , "Heroic narrative verse" , "eg Beowulf" , "long poem telling of heroic deeds" .)